compared to 18% on sugar pill. it is proven to reduce the urge to smoke. i did have an unopen pack of cigarettes in my purse and i said, "what the heck, i don't need these..." ...i said, you know, "bye, i don't need you anymore, you're not my crutch, i don't need a crutch." (announcer) talk to your doctor about chantix and a support plan that's right for you. some people have had changes in behavior, hostility, agitation, depressed mood and suicidal thoughts or actions while taking or after stopping chantix. if you notice agitation, hostility, depression or changes in behavior, thinking or mood that are not typical for you, or if you develop suicidal thoughts or actions, stop taking chantix and call your doctor right away. talk to your doctor about any history of depression or other mental health problems, which can get worse while taking chantix. some people can have allergic or serious skin reactions to chantix, some of which can be life threatening. if you notice swelling of face, mouth, throat or a rash stop taking chantix and see your doctor right away. tell your doctor which medicines you are taking as they may work differently when you quit smoking. chantix dosing may be different if you have kidney problems.